Project Summary/Abstract While prominent theories of addiction implicate physical dependence as a key predictor of drug use and relapse, the limited available research among Latinos has generally found that physical dependence has limited utility for predicting cessation. Further, Spanish-language instruments for measuring dependence multidimensionally have demonstrated poor psychometric structure among Spanish-speaking Latino smokers. These studies suggest that the mere translation of existing measures may not be adequate for developing effective assessments of tobacco dependence for Spanish-speaking smokers. Rather, there is critical need for an in-depth examination of the appropriateness of dependence scale translations and the relevance of item content for Spanish-speaking Latino smokers. As such, the aim of the current study is to use a mixed-methods approach to develop a theoretically grounded, multidimensional measure of smoking dependence and motives for smoking based on established measures but that is appropriate, reliable, and valid for Spanish-speaking smokers. We propose a four-phase study. Phase 1 will consist of cognitive testing of Spanish translations of the Wisconsin Inventory of Smoking Dependence Motives (WISDM) and Nicotine Dependence Syndrome Scale (NDSS) items to identify potential problems with the items as currently translated. Phase 2 will consist of in-depth interviews of the lived experience of dependence among Spanish-speaking smokers of Mexican origin to inform item refinement and development of additional items. Phase 3 will consist of item refinement and development informed by data gathered in Phases 1 and 2. Phase 4 will consist of validation of the resulting refined Brief WISDM and NDSS scales, as well as an examination of the entire pool of resulting items for potential development of a different and possibly more appropriate measure. Such a project stands to significantly impact research among Latinos across the tobacco continuum by allowing for more valid assessments of dependence among Latinos, which could lead to novel culturally relevant knowledge of the processes involved in smoking initiation, maintenance, cessation and relapse.